1. Field of the Invention
The present invention relates to an electromagnetic power supplying apparatus.
2. Description of Related Art
There is disclosed a method for supplying electric power to an electric motor vehicle in U.S. Pat. Nos. 4,347,472, 4,496,896 and Japanese Unexamined Patent Publication (KOKAI) No. 63-73,837. In the method, a secondary core with a secondary coil wound therearound is fixed on the front or on the bottom of an electric motor vehicle driven with a battery, and a primary core with a primary coil wound therearound is fixed on the ground. The electric motor vehicle is operated so as to position and join the primary core and the secondary core. Thus, a closed magnetic circuit with a gap is constituted between the primary and secondary cores, thereby supplying electric power to the electric motor vehicle.
However, in the conventional method disclosed in the aforementioned publications, it is extremely hard to position the primary and secondary cores, and accordingly it is inevitable to permit to roughly carry out the positioning. Such rough positioning inevitably results in the deteriorated electric power conversion efficiency (i.e., the secondary effective electric power/the primary effective electric power). In order to improve the electric power conversion efficiency, it is inevitable to enlarge the primary and secondary cores, but it is impossible to sharply improve the electric power conversion efficiency only by enlarging the cores. In addition, in the conventional method, in accordance with the configurations and positions of the primary cores fixed on the ground, the configurations and positions of the secondary cores fixed on the body of the electric motor vehicle must be determined. Accordingly, a heavy restriction is imposed on designing the electric motor vehicle.